1. Field of the Invention
The present invention relates generally to the coating of what are generally referred to as "traffic surfaces," namely generally horizontally extending surfaces such as roads, driveways, parking lots, walkways, tennis courts, flat roofs, rainwater catchments and the like wherein the surface areas to be covered are of sufficient size to warrant the use of a coating machine. For convenience, these surfaces are referred to herein as "traffic surfaces," it being understood, however, that this term is not used in a restrictive sense and is not limited in scope to surfaces which accommodate vehicular traffic.
2. Prior Art
Traffic surfaces are exposed to wear and often to the effects of the elements, with the result that they are subject to deterioration. Accordingly they require protective coatings to extend their useful lives. These coatings may be applied at the time the surface is constructed, but are more frequently applied after a certain amount of use in order to restore the surface to a desirable condition.
In some cases, a coating is applied manually to a traffic surface using one or more long-handled applicators; however, if the surface area to be treated is sufficiently large, it is preferably treated by mobile equipment, such as machines which have tanks for carrying liquid or slurry-type coating material, dispensing apparatus for metering the coating material or materials onto the surface to be treated, and mechanisms for spreading and applying the coating in a thin uniform layer. In some cases, it is advisable to apply particulate material such as sand to the surface to improve frictional properties. Usually this has been done by separately applying the sand through its own dispensing mechanism.
A problem with previously proposed coating applicator machines is that they are generally intended for traveling along highways or other unobstructed surfaces in a basically unidirectional fashion, and are not well suited for working in confined or irregularly shaped areas. Moreover, the spreading and applicator tools used by these machines are not well suited for treating surfaces which have significant surface variations or which require a repetitive blading action to effect proper feeding and/or troweling of material into and about large cracks; nor are they well suited to the execution of such sharp sudden changes in direction as are required where a surface area to be treated is closely confined and/or where it is found necessary to refinish a particular portion of the surface. A significant limitation of prior applicator proposals is their inability to effectively admix in situ such materials as epoxy substances, fibrous, beaded or heavy particulates and/or quick setting soluble substances to form uniform slurry compositions.
Another problem with previously proposed machines is that they require power-driven propulsion units. This requirement renders most previously proposed machines expensive and bulky. In finishing smaller surfaces such as tennis courts, residential driveways, and the like, these heavy power-driven machines may do damage to the surfaces being treated; moreover, their lack of maneuverability inhibits proper surface treatment.
A further problem with most previously proposed machines is that they are of complex and expensive construction, whereby their relatively large purchase prices often render these machines unavailable to some small companies.
3. The Parent Case
The referenced Parent Case addresses certain of the foregoing and other drawbacks of prior proposals by providing a novel and improved system for applying coatings to traffic surfaces. However, there remains a need for a simple and inexpensive system for spreading and applying surface coating ingredients utilizing a machine which is manually maneuvered and which is well suited to accommodate traffic surfaces of moderate size which have closely confined boundaries, changing contours, and/or surface irregularities. As will be apparent from the description which follows, the present invention represents an extension of the system development work which forms the subject matter of the referenced Parent Case. As will also be apparent, certain of the improvements which form the subject matter of the present invention may be advantageously used with the system of the Parent Case.